As a continuous kneading device that continuously kneads a material such as resin, there has been a continuous kneading device disclosed in Patent Literature 1, or the like. The continuous kneading device of Patent Literature 1 includes an internally hollowed barrel and a pair of kneading rotors housed in the barrel. The pair of kneading rotors is disposed so as to make their respective axes be substantially parallel to each other and allowed to rotate in respective directions different from each other. In the continuous kneading device, a material supplied into the barrel is led to between the kneading rotors rotating in the directions different from each other and kneading screws provided in the kneading rotors apply shearing forces to the material to thereby knead the material.
In recent years, it is required to knead a hard-to-knead material, which causes the need for further improvement of a kneading ability of the continuous kneading device. This improvement of the kneading ability can be achieved, for example, by increasing mesh between the kneading rotors. In the case of the continuous kneading device of Patent Literature 1, making the inter-axis distance between respective axes of the pair of kneading rotors be smaller than a rotational outer diameter of kneading flights enables the kneading rotors to be brought into mesh.
Increasing the degree of the mesh of the kneading rotors, however, involves a marked increase in a load (a kneading load) applied to the kneading rotors during the kneading. Specifically, making the kneading rotors be close to each other for increasing the mesh degree causes a large kneading load to be applied in a direction of separating the kneading rotors from each other. The kneading load can adversely affect the kneading rotors or bearing that supports the kneading rotors, or the like.
For the reason, the conventional continuous kneading device cannot allow the mesh between the kneading rotors to be further increased, which brings the difficulty in adapting the continuous kneading device to a kneading resistant material.